1. Field of the Invention
The present invention relates to a method of minimizing power consumed by each node in a wireless network, and in particular, in a mesh network.
The present invention is supported by the Information Technology (IT) Research & Development (R&D) program of the Ministry of Information and Communication (MIC) and the Institute for Information Technology Advancement (IITA) [2005-S-038-03, Development of UHF RF-ID and Ubiquitous Networking Technology].
2. Description of the Related Art
Since sensor nodes in a wireless sensor network environment operate based on limited energy, much research has been conducted on low power operation thereof. In particular, since a general sensor node operating using batteries does not support low power, services provided by the sensor node can be blocked. Accordingly, research on a low power protocol has been actively conducted.
In zigbee MAC, a synchronous communicating method generally used includes adjusting the communication time of each node. A system using such method is formed of a plurality of nodes which can be classified into a general node, a router node, and a sink node. The general node is the lowest portion for performing time synchronization. The router node receives a beacon message from a sink node or another router node and transmits the beacon message to a lower router or a general node, thereby matching the time of each node. The sink node mainly performs time synchronization in a network and transmits synchronization information, such as policy and time, in a network to a general node or a router node. Such method hardly adjusts synchronization and supports low power.